Numerical study of the impact on high-pressure and evaporating spray behavior of nozzle cavitation at typical diesel engine conditions

摘要

In order to more accurately reproduce diesel sprays a strategy including measurement of nozzle inlet pressure at the realistic diesel injection condition, modeling of nozzle cavitating flow and detailed coupling of nozzle exit flow and spray was presented, moreover, the validity of this strategy was firstly verified against the quantitative spray data obtained by planar laser induced exciplex fluorescence (PLIEF) technique. Based on the above strategy, the effect of cavitation phenomenon on spray formation at the typical diesel engine condition was further evaluated. The final numerical results mainly clarified that the contribution of cavitation phenomena to primary breakup is quite appreciable, and subsequently the evolution of the high-pressure and evaporating diesel spray structure greatly changes as cavitation occurs inside fuel injection nozzles. Moreover, evaluating the effects of cavitation phenomena on realistic diesel spray cannot be only confined to primary breakup or near-nozzle field.